Background: Persistent vulval pruritus is common and may not be associated with signs of a primary vulval dermatosis. Patients with established vulval disease may develop contact sensitivity as a secondary problem after the application of topical therapy.
Objective: A retrospective study was performed to establish the prevalence of allergic contact dermatitis in patients with pruritus vulvae. In addition, the results of patch testing in women with vulval lichen sclerosus were compared with those in patients with primary pruritus vulvae and essential vulvodynia.
Methods: Over a 5-year period, 121 women with vulval problems were patch tested to the European Standard Series, selected preservatives, perfumes, local anesthetics, medicaments, and a vulval battery.
Results: Fifty-seven patients (49%) had one or more relevant allergic positive reactions. Medicaments or their constituents were the most common allergens to give reactions. Seven of the 16 patients (44%) with lichen sclerosus had positive reactions. Symptoms resolved or improved significantly in 67 patients (55.4%) overall. Six of the seven women with lichen sclerosus who had positive reactions noted an improvement in their symptoms. Patients who had a relevant allergy were much more likely to improve than those whose tests were negative (p < 0.001).
Conclusion: Patients with pruritus vulvae and lichen sclerosus are at high risk of contact sensitivity. Patch testing is useful in the management of these patients and many can be helped by allergen avoidance.